Select all the correct statements from the following:

options:

In the $1$s and $2$s complement representation, sign extension means replicating the sign bit as many times as needed

None of these

To compute the $10$s complement of a number, you subtract each digit of the given number from $9.$

A positive number in $1$s complement, $2$s complement and the sign$-$magnitude form have the same representation.

A negative number in $1$s complement, $2$s complement and the sign$-$magnitude form have different representations.